Polymer/Graphene Nanocomposites via 3D and 4D Printing-Design and Technical Potential

Graphene is an important nanocarbon nanofiller for polymeric matrices. The polymer-graphene nanocomposites, obtained through facile fabrication methods, possess significant electrical-thermal-mechanical and physical properties for technical purposes. To overcome challenges of polymer-graphene nanocomposite processing and high performance, advanced fabrication strategies have been applied to design the next-generation materials-devices. This revolutionary review basically offers a fundamental sketch of graphene, polymer-graphene nanocomposite and three-dimensional (3D) and four-dimensional (4D) printing techniques. The main focus of the article is to portray the impact of 3D and 4D printing techniques in the field of polymer-graphene nanocomposites. Polymeric matrices, such as polyamide, polycaprolactone, polyethylene, poly(lactic acid), etc. with graphene, have been processed using 3D or 4D printing technologies. The 3D and 4D printing employ various cutting-edge processes and offer engineering opportunities to meet the manufacturing demands of the nanomaterials. The 3D printing methods used for graphene nanocomposites include direct ink writing, selective laser sintering, stereolithography, fused deposition modeling and other approaches. Thermally stable poly(lactic acid)-graphene oxide nanocomposites have been processed using a direct ink printing technique. The 3D-printed poly(methyl methacrylate)-graphene have been printed using stereolithography and additive manufacturing techniques. The printed poly(methyl methacrylate)-graphene nanocomposites revealed enhanced morphological, mechanical and biological properties. The polyethylene-graphene nanocomposites processed by fused diffusion modeling have superior thermal conductivity, strength, modulus and radiation- shielding features. The poly(lactic acid)-graphene nanocomposites have been processed using a number of 3D printing approaches, including fused deposition modeling, stereolithography, etc., resulting in unique honeycomb morphology, high surface temperature, surface resistivity, glass transition temperature and linear thermal coefficient. The 4D printing has been applied on acrylonitrile-butadiene-styrene, poly(lactic acid) and thermosetting matrices with graphene nanofiller. Stereolithography-based 4D-printed polymer-graphene nanomaterials have revealed complex shape-changing nanostructures having high resolution. These materials have high temperature stability and high performance for technical applications. Consequently, the 3D- or 4D-printed polymer-graphene nanocomposites revealed technical applications in high temperature relevance, photovoltaics, sensing, energy storage and other technical fields. In short, this paper has reviewed the background of 3D and 4D printing, graphene-based nanocomposite fabrication using 3D-4D printing, development in printing technologies and applications of 3D-4D printing.